Temporal avoidance of interfering noise by common chiffchaff

Abstract Birds use their song to attract mates and repel rivals; therefore, their fitness depends strongly on efficient song transmission. However, an environment full of other sounds from various sources, including signals of other animals and increasing noise of human activities, can substantially impair species’ communication. To test the response of a wild population of common chiffchaffs to the introduction of artificial sounds that interfere and do not interfere with their songs, we conducted two playback experiments. In the first experiment, we compared the song rate of males during 5-minute periods of white noise matching entire frequency band of the species’ song, broadcast alternately with periods of silence. In the second experiment, we compared their song rate during 5-minute periods of the same white noise, broadcast alternately with noise lower and higher in frequency than species-specific spectrum. Common chiffchaff males sang significantly fewer songs during noise matching their frequency than during periods of silence or other kinds of noise. Our results indicate that high-amplitude continuous noise fully interfering with species’ song causes stronger constraining effect on vocal activity of common chiffchaffs than non-interfering noise. These findings, along with previous studies, show that the response to noise is species specific, and the topic of variation among birds in the strategies used still requires additional testing.